Re: [PATCH v6 02/11] irqchip: loongson-liointc: Workaround LPC IRQ Errata

[Jiaxun Yang]

ä 2020å3æ25æ GMT+08:00 äå9:52:26, Huacai Chen <chenhc@xxxxxxxxxx> åå:
>Hi, Jiaxun,
>
>On Tue, Mar 24, 2020 at 11:39 PM Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
>wrote:
>>
>> The 1.0 version of that controller has a bug that status bit
>> of LPC IRQ sometimes doesn't get set correctly.
>>
>> So we can always blame LPC IRQ when spurious interrupt happens
>> at the parent interrupt line which LPC IRQ supposed to route
>> to.
>>
>> Co-developed-by: Huacai Chen <chenhc@xxxxxxxxxx>
>> Signed-off-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
>> ---
>>  drivers/irqchip/irq-loongson-liointc.c | 16 ++++++++++++++--
>>  1 file changed, 14 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/irqchip/irq-loongson-liointc.c
>b/drivers/irqchip/irq-loongson-liointc.c
>> index 8b6d7b8ddaca..d5054e90eab8 100644
>> --- a/drivers/irqchip/irq-loongson-liointc.c
>> +++ b/drivers/irqchip/irq-loongson-liointc.c
>> @@ -32,6 +32,8 @@
>>
>>  #define LIOINTC_SHIFT_INTx     4
>>
>> +#define LIOINTC_ERRATA_IRQ     10
>> +
>>  struct liointc_handler_data {
>>         struct liointc_priv     *priv;
>>         u32                     parent_int_map;
>> @@ -41,6 +43,7 @@ struct liointc_priv {
>>         struct irq_chip_generic         *gc;
>>         struct liointc_handler_data     handler[LIOINTC_NUM_PARENT];
>>         u8                              map_cache[LIOINTC_CHIP_IRQ];
>> +       bool                            have_lpc_irq_errata;
>Maybe has_lpc_irq_errata?

Fixed, thanks.

>
>>  };
>>
>>  static void liointc_chained_handle_irq(struct irq_desc *desc)
>> @@ -54,8 +57,14 @@ static void liointc_chained_handle_irq(struct
>irq_desc *desc)
>>
>>         pending = readl(gc->reg_base + LIOINTC_REG_INTC_STATUS);
>>
>> -       if (!pending)
>> -               spurious_interrupt();
>> +       if (!pending) {
>> +               /* Always blame LPC IRQ if we have that bug and LPC
>IRQ is enabled */
>> +               if (handler->priv->have_lpc_irq_errata &&
>> +                       (handler->parent_int_map & ~gc->mask_cache &
>BIT(LIOINTC_ERRATA_IRQ)))
>> +                       pending = BIT(LIOINTC_ERRATA_IRQ);
>> +               else
>> +                       spurious_interrupt();
>> +       }
>>
>>         while (pending) {
>>                 int bit = __ffs(pending);
>> @@ -164,6 +173,9 @@ int __init liointc_of_init(struct device_node
>*node,
>>                 goto out_iounmap;
>>         }
>>
>> +       if (of_device_is_compatible(node, "loongson,liointc-1.0"))
>> +               priv->have_lpc_irq_errata = true;
>> +
>>         sz = of_property_read_variable_u32_array(node,
>"loongson,parent_int_map",
>>                                                
>&of_parent_int_map[0], LIOINTC_NUM_PARENT,
>>                                                 LIOINTC_NUM_PARENT);
>> --
>> 2.26.0.rc2
>>
>>
>
>Regards,
>Huacai Chen

-- 
Jiaxun Yang